An interesting case is presented of a 53-year-old male who was seen with a 10-year history of intermittent, unilateral nasal obstruction following a bilateral total inferior turbinectomy. A pedunculated mass was seen in the right posterior nasal space acting as a ball valve. This was removed and found to be residual turbinate tissue.

A -study of reported cases reveals that while the occurrence of ball-thrombus of the left atrium is unusual a ball-thrombus of the right atrium is very rare indeed. The first case report is that of McLeod, in 1883, and sixty-one years elapse before the next-that of Wright, Flynn, and Druet, in 1944. Radding in America and Moia et al. in Argentina each published a report of a case in 1951, and t...

In this paper are presented desing, testing and numerical analysis for two manufactured control valve trims. Valve trim is consisted of cage or dick stack, plug, stem seat. Size from app. 15.88 mm (0.625 in) up to 101.6 (4 suitable 3D metal plastic print, what in paper. Selective laser melting printing applied on the disc Even better material properties rest parts could be obtained. This great ...

An investigation into the mechanisms of failure of current Björk-Shiley cardiac valve prostheses is reported. Two failed valves, one apparently unfailed but defective valve, and one unused valve, were examined by scanning electron microscopy and metallographic section. In the first two valves (removed 12 and 23 months after implantation) fracture was associated with the welds joining the short ...

the ball and beam system is one of the most popular laboratory setups for control education. in this paper, we design a fuzzy pd cascade controller for a ball and beam system using asexual reproduction optimization (aro) technique. the ball & beam system consists of a servo motor, a grooved beam, and a rolling ball. this system utilizes a servo motor to control ball’s position on the beam. chan...

Cage‐like metal–organic frameworks (MOFs) are promising for hexane isomer separation, but their aperture sizes difficult to control precisely. Herein, a molecular valve strategy is proposed fine‐tune the of cage‐like MOFs, thereby enhancing separation performance isomers. Three novel isostructural namely Cu‐MO 4 ‐TPA, synthesized using different oxometallate anions (MO 2− , M = Cr, Mo, and W) l...

Heat-shock protein 43 (HSP43) of Caenorhabditis elegans is prominently expressed in the utse cell, which attaches the uterus to the hypodermis, the uv1 cells joining the vulva and the uterus, the spermathecal valve and junctions between cells of the spermathecal cage. In body-wall muscle, HSP43 forms a punctate pattern of circumferential lines, probably corresponding to regions where the hypode...

The long term performance characteristics of the 2400 and 1260 series of Starr-Edwards aortic prostheses were investigated by a follow up study of clinical outcome of 327 patients discharged from hospital with isolated aortic valve replacement. Follow up lasted for up to 10 years and was based on 1616 patient-years. The 2400 series cloth covered tracked valve was implanted in 182 patients from ...

The factors affecting the lubrication effect of a ball bearing without cage and containing functional slot are analyzed, including structural parameters slot, speed rolling element, deformation contact surface, in order to establish initial oil volume equation. Based on multiple mesh method Matlab programming, established model is solved by obtaining distribution rules film pressure, thickness,...

Sound spectroanalysis was carried out for diagnosis of malfunctioning prosthetic heart valves in 50 cases, which consisted of 31 mitral, 14 aortic, 4 mitral+aortic and 1 tricuspid valve replacements with the age ranging from 17 to 57 years. Types of prosthetic valves used in this series were Starr-Edwards silicon ball valves, metal ball valves, disc valves, Kay-Shiley valves, Smeloff-Cutter val...